A HEV uses a battery pack to supply electrical energy to an electric motor or an electric machine, which are operable to provide motive torque, in combination with, for example, an internal combustion engine. Given the dynamics associated with operation of a HEV, particularly the constant flow of power into and out of the battery, the battery plays a critical role in the operation of the HEV. Generally the battery has a limited life expectancy of usage before not satisfying specific performance criteria. The life expectancy might be specified in a manufacturer's warranty in terms of, for example, a period of time since the battery began use in the HEV and/or a mileage that the battery has travelled with the HEV before the battery underperforms. It is important for the lifespan of the battery to meet the manufacturer's warranty and customers' expectations.